Manufacture of carbonate filled sized paper



Patented May 5, 1931 UNITEDSTATES.

PATENT. OFFICE HAROLD ROBERT narrow, or LAWRENCE, mAssAcn'usnr'rs, ASSIGNOR TGIBAFFOLD rnocEss CORPORATION, A CORPORATION or mAssAcHusEr'rs MANUFACTURE or oAimo'NArE FILLED SIZED PA]? lmssutn No Drawing.

This invention relates to the manufacture of papernnd more particularly to an' alum is added to the paper mix at the Wet to end of the aper machme.

Gther ob ects and advantages of this invention will become apparent during the course oil the following description. a

In my copending application Serial No.

and claimed a process-wherein a sized carbonate tilled pet is made by adding a sizeand a size precpitant to a paper mix in a heater or similar-machine, the sizing edect of the restoring agent, such as alum, to the mix at the Wet end of the paper machine. I have discovered that a satisfactorily sized paper can be produced by treating a paper-m1 in a manner similar to that disclosed 1n my copending application referred to by omit.

' ting the addition of a size precipitant in the beater and precipitating the size at or subsequent to the point where the mix is dilu prior to its passage on to the web-forming device of the paper machine.

in the preferred practice of my process it add to fibrous material in a heater or similar machine, or in a mixer or similar device when a heater is not employed, carbonate filler of the character hereinafter referred to and size, such as rosin size. Other ingrients such as coloring mattermay be added if desired. This mix is then passed through the usual preliminary paper making procedure and at or subsequent to the point when the mix .15 diluted prior to the passageithereof on to a to web-forming device of a. papermachine I add Application filed September 5, 1928. Serial No. 304,172.

304,168, filed Sept. 5, 1928, l have described action product of the size and size precipi-. tant which is deteriorated by the carbonate filler being restored by adding a sizing re-- preferably continuously .to the mix a suitable size precipitant, such as alum, preferably in solution. In this manner, the size precipitant is added at a point where there will be a minimumof intimacy and time of contact of the constituents of the mix before the paper web is formed. The thus treated mix I is then passed on to a web-forming device and is subjected to the usual steps for completing the manufacture of finished paper. 1

It is necessary as indicated to add the size preci itant at or subsequent to the point of dilution of the mix, as I have found that if it be added when the mix is in relatively concentrated condition, and particularly when the relatively concentrated mix is subjected to agitation as is normal in stock-chests the sizing efifect is very quickly deteriorated even to the point of complete destruction. The sizing efi'ect even when the mix is in the diluted condition is gradually deteriorated, but is substantially unafiected within the time limits that the mix is maintained in the dilute state in the usual paper-making procedure.

Moreover, although agitation in the dilute state hastens to a certain extent the deterioration of the sizing efiect, the speed of deterioration is not nearly so pronounced as 'in the concentrated condition, and from a practical standpoint I have found that the agitation to which the diluted mix is subjected prior to delivery onto the web-forming device does not deteriorate the sizing effect to a substantial degree.

Of course the size may be added at any point prior to web toation other than in the beater, even after the addition of the alum,

' but experiments do not indicate that any substantially better sizing efiect is obtained thereby although the tendency to foam may be somewhat lessened, and-such addition therefore can be considered the substantial equivalent of adding size in the beater.

The alum solution need not be added diwater with which the mix is diluted. If the V alum be added to the tray water, only a briei time interval should elapse before the so treated tray water is used for dilution. 4

Although substantially more foam is produced in the-herein described process than in the process referred to in my copending application, (except possibly in that modification wherein size would be added at the wet end of the paper machine after the alum addition), nevertheless the foam is altered in character by the size precipitant before the mix is passed onto the web-forming device, so that what foam is not held back in the rifliers or the like is ofsuch nature that it causes substantially no trouble during the formation of the web, and the paper produced by this process has been found to be of a satisfactory quality. Moreover inasmuch as the amount of alum used in the present process is less than that used in the process set forth in my copending application referred to above, the present process therefore results in a more economical operation.

An illustrative furnish suitable for use in the practice of my invention is as follows:

Materials added in beater Pounds Fibrous furnish, e. g. sulphite and soda pulps 1700 Size, e. g. rosin size Carbonate filler, e. g. calcium carbonate magnesium hydroxide-" 300 Material added to min: proportionately and Fibrous furnish, e. g. approximately equal parts of sulphite, soda and old paper stock Size, e. g. rosin size Carbonate filler, e. g. calcium carbonate magnesium hydroxide 300 Material added to mix proportionately and continuously on, dilution Pounds Size precipitant, e. g. alum (A12(SO)3.18H20) 105 In the above formulae, the weights of size and carbonate filler refer to the bone dry basis, the weights of all other ingredients being given on the air dry basis.

As indicated above, the primary object of my invention is to obtain sizing in a paper mix containing carbonate filler by the addition of a size precipitant such as alum. Under conditions ordinarily obtaining in paper mixes, this size precipitant would react chemically with the carbonate filler and thus be destroyed. However, I am able to obtain the desired effect of this size precipitant in the paper mix and thus obt l-lIl sizing by adjusting conditions under which the size precipitant is added so as to substantially prevent it from reacting chemically with the carbonate filler. There is therefore substantially no conversion of the carbonate filler into a neutral compound by reaction with the carbonate filler, nor any. definite amount of size precipitant used, the illustrative furnishes given herein indicate that normally the carbonate filler constitutes a substantial percentage of the total furnish, and consequently of the paper produced, and that it is present in the furnish in an amount greatly in excess of the stoichiometrical equivalent of the size precipitant added. Thus it will be noted that even were conditions such that reaction between the size precipitant and the carbonate filler could take place and go to completion which is substantially not the case in my invention, the final result would not be a neutralization of the mix but rather a using up of the size precipitant, and the mix would remain on the alkaline side owing to the excess carbonatefiller present. It is thus apparent that my process, in which a paper is produced containing a substantial quantity of carbonate filler, is wholly unrelated to any paper making procedure wherein alum or the like is added to a paper mix for the purpose of substantially neutralizing the same so that the final paper will contain substantially no alkaline constituents.

In place of alum as a size precipitant I may use with a measure of success an acid such as sulphuric acid (H SO an acid salt such as sodium bisulphate (NaHSO or a salt of a trivalent metal, such as ferric iron or the other salts of aluminum. Of the aluminum salts available I may use the chloride or the like, but I prefer to use ordinary alum.

In place of rosin size I may use satisfactorily in the practice of my process other sizes, for example soaps, such as oleates, or any other size derived by treatment v. ith an alkaline substance or the like from material originally of acid characteristics or of a partially or completely saponifiable nature, such as saponified beeswax.

When I use the term rosin size it is to be understood that I mean it to include any material produced by the action of alkali, generally in aqueous solution, on rosin, or on natural or synthetic resin acid or acids, regardless of the exact composition of the product, or the varying composition which diiferent samples may possess.

When I use the word paper herein, I use it in the broad sense to include products of manufacture of all types and of all weights and thicknesses, which contain as an essential constituent a considerable amount of pre pared-fibre and which are capable of being produced on a Fourdrinier, cylinder, or other forming, felting, shaping or molding machine.

By the term carbonate filler as employed herein, is intended to be included calcium carbonate, of which lime mud from the causticizing process is one form; calcium carbona-te magnesium basic carbonate employed pa ers, broke, or the like.

a trivalent metal under .in the paper disclosed in my U. S. Patent No.

filler is also intended to include fibrous material and/or other material such as paper coating constituents or the like containing one or more compounds of the character referred to, such as old papers or similar y the term wet end of the paper machine talities employed in paper manufacture by .which and/or inwhich a relatively concentrated paper mix is diluted, and treated, conveyed or fed up to the point of web-formation, such as the mixingbox, regulating and proportioning devices, rifiers, troughs, screens, head boxes, inlets, and the like, including also inst-runientalities used in the white water cycle. J

While I have described in detail the preferred embodiment of my invention, it is to be understood that the details of procedure, the proportions of ingredients, and the arrangement of steps may be widely varied without departing from the spirit of the invention or the scope of the subjoined claims.

it claim:

, 1. The method of manufacturing a sized.v paper filled with carbonate filler comprising material, carbonate filler, and size, a size precipitant under conditions favoring the minimizing of the intimacy and time of contact of the constituents of the mix, and thereafter making paper therefrom.

3. The method of manufacturing asized 7 paper filled with carbonate filler comprising adding to a paper mix containing fibrous material, carbonate filler, and rosin size, a size precipitant under conditions favoring the .minimizing of the'time of contact of the constituents of the mix, and thereafter making paper therefrom; p I

t. The method of manufacturing a sized paper filled with carbonate filler comprising adding to a paper mix containing fibrous material", carbonatefiller, and size, a salt of conditions favoring ysically associated the-minimizin of the time of contact of the constituents o the mix, and thereafter making paper therefrom.

5. The method of manufacturing a sized paper filled with carbonate filler comprising adding to a paper mix containing fibrous minimizin of the time of contact of the constituents o the mix, and thereafter making paper therefrom.

6. The method of manufacturing a sized paper filled with carbonate filler comprising adding to a paper mix containing fibrous material, carbonate filler, and size, alum under conditions favoring the minimizing of the time of contact of the constituents of the mix, and thereafter making Eaper therefrom. is intended to be included those instrumenof a trivalent metal under conditions favoring the minimizing of the time of contact of the constituents of the mix, and thereafter making paper therefrom.

8. The method of manufacturing a sized.

paper filled with carbonate filler comprising adding to. a paper mix containing fibrous material, carbonate filler, and rosin size, alum under conditions favoring the minimizing of the time of contact of the constituents of the mix, and thereafter making paper therefrom.

9. The step in a method of manufacturing a sized paper filled with carbonate filler comprising a ding at the wet end of the paper machine to a paper mixcontaining carbonate filler a material forprecipitating size.

- material, carbonate filler, and size, a saltof aluminum under conditions favoring the- 10. The step in a method of manufacturing I a sized paper filled with carbonate filler comprising adding at the wet end of the paper machine to a aper mix containing carbonate filler a material for precipitating size, comprising salt of a trivalent metal.

. 11. The step in a method of manufacturing a sized paper filled with carbonate filler comprisingadding at the wet end of the paper machine to a paper mix containing carbonate filler a material for precipitating size, comprisin alum.

12. 'i it stop in a method of manufacturing a sized paper filled with carbonate filler comprising adding to a paper mix contaming fibrous material, carbonate filler, and a saponified material, a size precipitant at the wet end of the aper machine.

13. The step in a method of manufacturing a sized paper filled with carbonate filler comrising adding to a paper mix containing fibrous material, carbonate filler, and s1ze, a sizeprecipitant at the wet end of the paper machine.

14. The step in a method of manufacturing a sized pa er filled with carbpnate finer comprising a ding to a paper mix contaming fibrous material, carbonate filler, and rosin size, a salt of a trivalent metal at the wet end of the paper machine.

15. The step in a method of manufacturing a sized paper filled with carbonate filler comprising adding to a paper mix containing fibrous material, carbonate filler, and rosin size, alum at the wet end of the paper machine.

16. The step in a method of manufacturing a sized paper filled with carbonate filler comprising adding alum to a paper mix containing fibrous material, carbonate filler, and rosin size, when said paper mix is in dilute condition prior to its delivery to the webforming device of the paper machine.

17. The step in a method of manufacturing a sized paper filled with carbonate filler comprising adding to a paper mix containing fibrous material, rosin size, and carbonate filler comprising an alkaline earth metal carbonate, alum at the wet end of the paper machine.

18. The step in a method of manufacturing a sized paper filled with carbonate filler comprising adding to a paper mix containing fibrous material, rosin size, and carbonate filler comprising calcium carbonate, alum at the wet end of the paper machine.

19. The step in a method of manufacturmg a sized paper filled with carbonate filler comprising adding to a paper mix containing fibrous material, rosin size and carbonate filler comprising calcium carbonate and magnesium compound, alum at the wet end of the paper machine.

20. The step in a method of manufacturing a sized paper filled with carbonate filler comprising adding to a paper mix containing fibrous material, rosin size, and carbonate filler comprising calcium carbonate magnesium hydroxide, alum at the wet end of the paper machine.

In testimony whereof I aflix my signature.

HAROLD ROBERT RAFTON. 

